The present invention relates to a rapid-stop device for an externally driven automatic weapon of the type including a straight-action breech block driven by a control roller or drum. More particularly, the present invention relates to such a rapid-stop device which includes an axial displacement means for, at least in the case of a weapon malfunction, activating brake shims to interrupt the rotary movement of the control roller for the straight-action breech block, and which is disposed in the weapon housing.
Such a rapid-stop device is known from Federal Republic of Germany DE-OS 3,307,882, published Sep. 6, 1984. The rapid-stop device disclosed in this reference prevents, in the case of a malfunction, further rotation of two control rollers provided for a straight-action breech block. The device is disposed at the rear end of each control roller and requires a detonator which is flanged to the breech housing to activate brake shims for sudden braking. In the case of a malfunction, a longitudinally displaceable claw shaft is detained, under the gas pressure developed by the detonator, in pockets disposed at the frontal face of the respective control roller, with it being necessary to first shear off a shear pin which holds the claw shaft in the rest position. A helical gear disposed between the claw shaft and the lamella coupling then transfers the braking moment of the lamella coupling to the drive shaft.
It is considered a drawback of this rapid-stop device that after each malfunction, the rapid-stop device must be disassembled so that the shear pin and the detonator can be replaced. Moreover, the firing reliability of the detonator may be adversely affected, for example due to contact with it, particularly if there are further switching units. It is a further drawback that this rapid-stop device requires a large amount of expensive space within the breech housing. Due to this structure and particularly due to this mode of operation, this rapid-stop device is also not suitable for an interruption of the normal firing operation. The braking process required during shutdown to interrupt the firing operation necessitates a separate catching device in which, for example, a catch lever or camming pawl, clamped by a spring, engages in a catch edge or recess as disclosed in U.S. Pat. No. 4,193,335.